Crossing construction method of steel cofferdam inner support and main pier body

Abstract

The present application relates to a steel cofferdam inner support and main pier body intersection construction method, comprising: setting up a well-shaped inner support in the cofferdam area of the steel cofferdam; determining the construction position of the main pier body; pouring the main pier pile cap at the construction position of the main pier body; removing the remaining well-shaped inner support layer by layer from bottom to top, pouring the current layer well-shaped inner support corresponding segment pier body after removing each layer of well-shaped inner support, and continuously constructing until the pouring of the main pier body is completed. In the case of intersection operation based on the main pier body and the steel cofferdam inner support, the present application optimizes the design of the inner support, on the one hand, simplifies the steel cofferdam inner support structure, fully utilizes the strength of the material itself, reduces the input of the inner support material, and at the same time increases the operable space during the construction of the main pier body, ensuring the convenience of component installation and removal; on the other hand, the steel cofferdam inner support system is optimized, part of the steel cofferdam inner support is converted on the main pier body, which is beneficial to the stability of the steel cofferdam during the later removal construction.

Description

Technical Field

[0001] This invention belongs to the field of bridge construction, specifically relating to a method for the cross-construction of steel cofferdam internal supports and main pier bodies. Background Technology

[0002] During the construction of steel cofferdams, the difference in elevation between the internal and external water bodies or soil will exert certain pressure on the cofferdam. Internal bracing is often required to improve the overall structural rigidity and resist deformation. In deep foundation pit or deep water foundation construction, steel cofferdams are generally quite high and require a large number of internal bracings to ensure construction safety. Furthermore, the height of the steel cofferdam means that part of the main pier needs to be constructed inside the cofferdam, creating a situation where the reinforcement and removal of the internal bracing of the steel cofferdam overlaps with the segmental construction of the main pier.

[0003] Based on past engineering experience, when the main pier body and the steel cofferdam are constructed at the same intersection, internal bracing is usually used to avoid direct contact, such as using figure-eight or X-shaped internal bracing. However, due to the characteristics of the stress (the internal bracing is not perpendicular to the steel cofferdam wall, resulting in a component force), these bracing methods cannot fully utilize the material's strength. Therefore, when using these methods for internal bracing, to ensure structural safety, using denser internal bracing will, on the one hand, reduce the working space inside the steel cofferdam, increasing the workload of later dismantling work; on the other hand, it will also interfere with the main pier construction, increasing the construction risk. Summary of the Invention

[0004] The purpose of this invention is to provide a method for the cross-construction of the internal support of the steel cofferdam and the main pier body, so as to overcome the above-mentioned technical defects.

[0005] To solve the above-mentioned technical problems, the present invention provides a method for the cross-construction of the internal support of the steel cofferdam and the main pier body, including:

[0006] A grid-shaped internal support is installed within the enclosure area of ​​the steel cofferdam;

[0007] Determine the construction location of the main pier body;

[0008] The main pier cap is poured at the construction location of the main pier body;

[0009] The grid-shaped internal supports outside the construction location of the main pier body are retained. The remaining grid-shaped internal supports are removed layer by layer from bottom to top. Each time a grid-shaped internal support is removed, the corresponding segment of the pier body is poured. The construction is carried out continuously in an overlapping manner until the pouring of the main pier body is completed.

[0010] The grid-shaped internal support is composed of several layers of grid-shaped frames stacked together. Each layer of grid-shaped frame includes transverse inward supports and longitudinal inward supports. The transverse inward supports and longitudinal inward supports are perpendicularly intersected to form a grid.

[0011] Determine the construction location of the main pier body, including:

[0012] The central grid of the grid-shaped frame and the extended areas on both sides along the transverse direction of the bridge are designated as the preliminary construction positions for the main pier body.

[0013] Adjust the initial pre-set construction position so that the longitudinal inward support is within the orthographic projection range of the main pier body, while the transverse inward support is outside the orthographic projection range of the main pier body.

[0014] The internal supports in the grid pattern are numbered sequentially from bottom to top as section 1, section 2, ..., section m.

[0015] The main pier sections are numbered sequentially from bottom to top as the first pier section, the second pier section, ..., the nth pier section;

[0016] Both m and n are positive integers.

[0017] Retain the grid-shaped internal supports outside the construction location of the main pier body, and dismantle the remaining grid-shaped internal supports layer by layer from bottom to top. After each layer of grid-shaped internal supports is dismantled, pour the pier body segment corresponding to the current layer of grid-shaped internal supports. Continue this cross-construction until the main pier body is completed. Specifically, this includes:

[0018] For the construction of the first pier section, the inward support along the bridge where the middle grid of the first support is located is removed, while the remaining grid-shaped inner supports are retained. Concrete is poured to form the first pier section, and wedge-shaped pads are installed at the intersection of the middle grids of the first support to support the first pier section.

[0019] For the construction of the second pier section, the inward support along the bridge where the middle grid of the second support is located is removed, while the remaining grid-shaped inner supports are retained. Concrete is poured to form the second pier section. Wedge-shaped pads are installed at the intersection of the middle grids of the second support section to support the second pier section.

[0020] Repeat the above steps, continuously carrying out the construction in a staggered manner, until the main pier body is poured.

[0021] The plane containing the m-th support is located at the waist of the n-th pier section, where m = n.

[0022] The beneficial effects of this invention are as follows:

[0023] In the case of overlapping operations between the main pier body and the internal support of the steel cofferdam, this invention optimizes the design of the internal support method. On the one hand, it simplifies the internal support structure of the steel cofferdam, makes full use of the inherent strength of the materials, reduces the input of internal support materials, and increases the operable space during the construction of the main pier body, ensuring convenient installation and dismantling of components. On the other hand, it optimizes the internal support system of the steel cofferdam, transferring part of the internal support of the steel cofferdam to the main pier body, which is beneficial to the internal stability of the steel cofferdam during the later dismantling construction.

[0024] To make the above description of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0025] Figure 1 This is a top-down view of the construction of the steel cofferdam's internal support and the main pier body.

[0026] Figure 2 This is a cross-sectional view of the intersection of the internal support of the steel cofferdam and the main pier body.

[0027] Figure 3 This is a schematic diagram of the wedge-shaped pad.

[0028] Figure 4 This is a diagram showing the construction process of the steel cofferdam's internal support and the main pier body.

[0029] Explanation of reference numerals in the attached figures:

[0030] 10. Steel cofferdam;

[0031] 20. Main pier cap;

[0032] 30. Main pier body;

[0033] 41. Transverse bridge inward support; 42. Longitudinal bridge inward support;

[0034] 50. Wedge-shaped pad;

[0035] 60. Main pier pile foundation;

[0036] 70. Bottom sealing concrete. Detailed Implementation

[0037] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0038] It should be noted that, in this invention, the upper, lower, left, and right in the figure are considered to be the upper, lower, left, and right of the cross construction method of the steel cofferdam internal support and the main pier body described in this specification.

[0039] Exemplary embodiments of the present invention will now be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0040] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0041] The construction of cofferdam internal supports and piers is mainly carried out in deep water areas, where the cofferdam is not a high pile cap and the cofferdam is tall. After the construction of the pile cap is completed, some piers are still in the water. The cofferdam must be retained until the piers emerge from the water. Due to the high external water head and high water pressure, the internal supports of the cofferdam cannot be removed. Therefore, the support structure must be changed to replace the supports on piers with sufficient strength and alternately construct the piers until they emerge from the water.

[0042] Please see Figure 1 This embodiment relates to a method for the cross-construction of the internal support of the steel cofferdam and the main pier body, including:

[0043] S1, a grid-shaped internal support is installed within the enclosure area of ​​the steel cofferdam 10.

[0044] The grid-shaped inner support is composed of several layers of grid-shaped frames stacked together. Each layer of grid-shaped frame includes transverse bridge inward support 41 and longitudinal bridge inward support 42. The two transverse bridge inward supports 41 and the two longitudinal bridge inward supports 42 are perpendicular to each other to form a grid.

[0045] When designing the internal support of the steel cofferdam, a certain margin is considered. This margin is reflected in the removal of one layer of inward support along the bridge 42 to ensure that there is still sufficient rigidity to resist external pressure and maintain the stability of the structure.

[0046] The grid-shaped internal support can significantly reduce material input and increase the internal construction space of the steel cofferdam.

[0047] S2, determine the construction location of the main pier body 30, including:

[0048] 201. The central grid and the two sides extending along the transverse direction of the bridge along the grid-shaped frame are designated as the preliminary construction positions for the main pier body 30. The central grid and the two sides extending along the transverse direction of the bridge along the grid can be referenced here. Figure 1 The rectangular frame shown is filled with a cross-sectional pattern.

[0049] 202. Adjust the initial pre-set construction position so that the longitudinal bridge inward support 42 is within the orthographic projection range of the main pier body 30, while the transverse bridge inward support 41 is outside the orthographic projection range of the main pier body 30. Specifically, during the foundation clearing process inside the steel cofferdam, following the principle of clearing one layer and reinforcing the next, a grid-shaped internal support is set according to the pressure difference between the inside and outside of the steel cofferdam. Among them, the longitudinal bridge inward support (transverse bridge inward support 42) inside the steel cofferdam is within the projection range of the main pier body 30, while the transverse bridge inward support 41 is outside the projection range of the main pier body 30.

[0050] S3, pour the main pier cap 20 at the construction location of the main pier body 30.

[0051] Please refer to the following after the main pier cap 20 is poured. Figure 2 The overall structure formed by the main pier cap 20, the bottom sealing concrete 70, and the main pier pile foundation 60 serves as a crucial constraint for the construction of the main pier steel cofferdam, effectively ensuring construction safety. At this time, the main pier cap 20 acts as a support, strengthening the rigidity of the cofferdam bottom and providing stable construction conditions for the main pier construction under deep foundation conditions.

[0052] It should be noted that before the overlapping construction, the internal supports of the grid pattern should be numbered sequentially from bottom to top as section 1, section 2, ..., section m. Figure 2 Taking the structure shown as an example, m=6, that is, there are 6 support sections, which are the 1st support section, the 2nd support section, the 3rd support section, the 4th support section, the 5th support section, and the 6th support section from bottom to top.

[0053] Similarly, the main pier sections 30 are pre-numbered from bottom to top as the first pier section, the second pier section, ..., the nth pier section, and so on. Figure 2 Taking the structure shown as an example, n=6, that is, there are 6 pier sections, which are the first pier section, the second pier section, the third pier section, the fourth pier section, the fifth pier section, and the sixth pier section from bottom to top. It should be noted that the numbering starts from the upper surface of the main pier cap 20.

[0054] Both m and n are positive integers.

[0055] It is worth mentioning that the construction height of each segment of the main pier body 30 is determined based on the spacing between the inner support layers. Specifically, after the main pier cap 20 is constructed, the construction height of the first segment of the main pier body should exceed the height of the first layer of the remaining steel cofferdam inner support, but should be lower than the height of the second layer of steel cofferdam inner support. That is, the plane where the m-th support segment is located is at the waist of the n-th pier body, where m = n. An example will be given below:

[0056] Taking the construction height of the first pier section as an example, please refer to... Figure 2The first pier section is higher than the first support section, and at the same time, the first pier section is lower than the second support section. In other words, the first pier section is located between the first support section and the second support section. For the purpose of explaining with m and n, it can also be considered that the plane where the first support section is located is located at the waist of the first pier section.

[0057] The reason why the plane of the m-th support is required to be at the waist of the n-th pier body, m=n, is to ensure that after some of the longitudinal inward supports 42 are removed, the main pier body 30 still has enough rigidity to resist external pressure and maintain the stability of the structure.

[0058] S4. Retain the grid-shaped internal supports outside the construction location of the main pier body 30, and remove the remaining grid-shaped internal supports layer by layer from bottom to top. After each layer of grid-shaped internal supports is removed, pour the corresponding segment of the pier body for the current layer of grid-shaped internal supports. Continue to carry out cross-construction until the pouring of the main pier body 30 is completed.

[0059] Specifically, it includes:

[0060] 401. Construction of the first pier section: Remove the middle grid of the first support section and the inward support 42 along the bridge, retain the remaining grid-shaped inner supports, pour concrete to form the first pier section, and install wedge-shaped pads 50 at the intersection of the middle grids of the first support section to support the first pier section.

[0061] After the first pier section is completed, once the final hydration peak of the concrete has passed, excess water evaporates, and the main body temperature gradually cools down, the concrete volume begins to shrink, and the concrete acquires a certain compressive strength, reaching 90% of the design strength. At this point, wedge-shaped pads 50 are installed at the corresponding positions of the removed internal supports (i.e., the intersection of the middle grids of the first support section) to transfer part of the steel cofferdam's internal support system to the main pier.

[0062] 402. Construction of the second pier section: Remove the inward support 42 along the bridge where the middle grid of the second pier section is located, retain the remaining grid-shaped inner supports, pour concrete to form the second pier section, and install wedge-shaped pads 50 at the intersection of the middle grids of the second pier section to support the second pier section.

[0063] Regarding the construction of the second pier section, the longitudinal inward support 42, where the middle grid of the second support is located, is removed. The length of the removal is the same as the length of the first support. Then, the main pier segment of the corresponding height is constructed. After the constructed segment meets the above requirements, the second layer of longitudinal inward support (i.e., the longitudinal inward support 42 where the middle grid of the second support is located) is transferred to the constructed main pier segment using wedge-shaped pads 50.

[0064] Repeat the above steps, continuously cross-constructing until the main pier body 30 is poured. In other words, cycle through the above process to remove the inward supports along the bridge in sequence, and construct the corresponding main pier segments until the main pier body construction within the steel cofferdam area is completed.

[0065] by Figure 2 Taking the six-section support shown as an example, the following explains their cross-construction process. Inner support beam C refers to the middle grid of the current grid-shaped inner support, extending inwards along the bridge (42). Inner support beam B refers to the remaining grid-shaped inner support, extending inwards along the bridge (42). See [reference needed]. Figure 4 Following the direction of the arrows, each image corresponds to one of the following steps:

[0066] Step 1: Remove the first-floor internal support beam C and construct the tower columns below the second-floor internal support beam;

[0067] Step 2: After the constructed tower column reaches the design strength, support the first-layer inner support beam B on the constructed tower column.

[0068] Step 3: Remove the second-floor inner support beam C and construct the tower columns below the third-floor inner support beam;

[0069] Step 4: After the constructed tower column reaches the design strength, support the second-layer inner support beam B on the constructed tower column.

[0070] Step 5: Remove the third-floor internal support beam C and construct the tower columns below the fourth-floor internal support beam;

[0071] Step 6: After the constructed tower column reaches the design strength, support the third-layer inner support beam B on the constructed tower column.

[0072] Step 7: Remove the fourth-floor internal support beam C and construct the tower columns below the fifth-floor internal support beam;

[0073] Step 8: After the constructed tower column reaches the design strength, support the fourth-floor inner support beam B on the constructed tower column.

[0074] Step 9: Remove the fifth-floor internal support beam C and construct the tower columns below the sixth-floor internal support beam;

[0075] Step 10: After the constructed tower column reaches the design strength, support the fifth-floor inner support beam B on the constructed tower column.

[0076] Step 11: Remove the sixth-floor internal support beam C and construct the remaining tower columns.

[0077] See the working diagram of wedge-shaped pad 50. Figure 3 The wedge-shaped pad 50 has a flat surface on the left (close to the main pier body 30) and a curved surface on the right (close to the transverse bridge inward support 41). The flat surface on the left is close to the main pier body 30, and the curved surface on the right is close to the transverse bridge inward support 41. That is, the wedge-shaped pad 50 is sandwiched between the main pier body 30 and the transverse bridge inward support 41.

[0078] In general, the construction method for the combined construction of the internal support of the steel cofferdam and the main pier body mainly involves the following steps:

[0079] (1) Based on the internal and external pressure difference, the steel cofferdam internal support is set up. When selecting materials and quantities, the construction height of the pier should be taken into account, and there should be a certain margin within a certain range, allowing the removal of one section of the steel cofferdam internal support to maintain the overall stability of the structure.

[0080] (2) After the pier cap construction is completed, the inner supports of the first layer of steel cofferdam along the middle section of the bridge are removed, including the projected area of ​​the main pier body and its outer 50cm range, such as... Figure 1 As shown, the distance between the plane containing the long side of the main pier body 30 (i.e., parallel to the transverse bridge inward support 41) and the transverse bridge inward support 41 is 50cm, the purpose of which is to place the wedge-shaped pad 50.

[0081] (3) Construct the tower columns below the second-floor internal support;

[0082] (4) After the concrete strength of the tower column reaches more than 90% of the design strength, restore the internal support and support the steel pipe on the constructed pier column through wedge-shaped pads.

[0083] (5) Remove the second layer of inward support along the bridge and construct the tower columns below the inner support beam of the third layer;

[0084] (6) After the constructed tower column reaches the design strength, the second layer of inner support is supported on the constructed tower column by wedge-shaped pads;

[0085] (7) Repeat steps (5)-(6) above until the cross-construction is completed.

[0086] This invention optimizes the internal support design when there is overlapping work between the main pier body and the steel cofferdam's internal support. On one hand, it simplifies the internal support structure of the steel cofferdam, fully utilizes the inherent strength of the materials, reduces the input of internal support materials, and simultaneously increases the operational space during the construction of the main pier body, ensuring convenient component installation and dismantling. On the other hand, it optimizes the internal support system of the steel cofferdam, transferring a portion of the internal support to the main pier body, which is beneficial for the internal stability of the steel cofferdam during later dismantling work.

[0087] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A method for the cross-construction of the internal support of a steel cofferdam and the main pier body, characterized in that, include: A grid-shaped internal support is installed within the enclosure area of ​​the steel cofferdam (10); The grid-shaped inner support is composed of several layers of grid-shaped frames stacked together. Each layer of the grid-shaped frame includes a transverse bridge inward support (41) and a longitudinal bridge inward support (42). The transverse bridge inward support (41) and the longitudinal bridge inward support (42) are perpendicularly intersected to form a grid. The grid-shaped inner support has a reserve to ensure that after the removal of one layer of the inward support (42) along the bridge, the steel cofferdam (10) still has enough rigidity to resist external pressure and maintain structural stability. Determine the construction location of the main pier body (30); The main pier cap (20) is poured at the construction location of the main pier body (30); The middle grid of the grid-shaped inner support is removed layer by layer from bottom to top, and the inner support (42) along the bridge is removed. The remaining grid-shaped inner supports are retained except for the construction position of the main pier body (30). Each time a layer is removed, the corresponding segment of the pier body of the grid-shaped inner support of the current layer is poured. The construction is carried out continuously and crosswise until the pouring of the main pier body (30) is completed.

2. The method for the cross-construction of the steel cofferdam internal support and the main pier body as described in claim 1, characterized in that, The determination of the construction location of the main pier body (30) includes: The central grid and the extended areas on both sides along the transverse direction of the grid frame are designated as the preliminary construction positions of the main pier body (30). Adjust the initial preset construction position so that the longitudinal bridge inward support (42) is within the orthographic projection range of the main pier body (30), while simultaneously ensuring that the transverse bridge inward support (41) is outside the orthographic projection range of the main pier body (30).

3. The method for the cross-construction of the steel cofferdam internal support and the main pier body as described in claim 1 or 2, characterized in that, The grid-shaped internal supports are numbered sequentially from bottom to top as the 1st support section, the 2nd support section, ... the mth support section; The main pier body (30) is numbered sequentially from bottom to top as the first pier body, the second pier body, ... the nth pier body; Both m and n are positive integers.

4. The method for the cross-construction of the steel cofferdam internal support and the main pier body as described in claim 3, characterized in that, The middle grid of the grid-shaped inner support is removed layer by layer from bottom to top, along the bridge's inward support (42). The remaining grid-shaped inner supports, except for the main pier body (30), are retained. Each layer is removed, and the corresponding segment of the pier body is poured. This process is repeated until the main pier body (30) is completed. Specifically, this includes: For the construction of the first pier section, the middle grid of the first support section is removed and the inner support (42) along the bridge is removed. The remaining part of the grid-shaped inner support is retained, and concrete is poured to form the first pier section. Wedge-shaped pads (50) are installed at the intersection of the middle grids of the first support section to support the first pier section. For the construction of the second pier, the middle grid of the second support is removed along the bridge inward support (42), the remaining part of the grid-shaped inner support is retained, concrete is poured to form the second pier, and wedge-shaped pads (50) are installed at the intersection of the middle grids of the second support to support the second pier. Repeat the above steps, continuously cross-construction until the main pier body (30) is poured.

5. The method for the cross-construction of the steel cofferdam internal support and the main pier body as described in claim 3, characterized in that, The plane containing the m-th support is located at the waist of the n-th pier section, where m = n.

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